It has been 33 years since Bhopal witnessed one of the largest industrial disasters in the world. On December 2, 1984, 40 tonnes of methyl isocyanate (MIC) leaked from a tank at the Union Carbide Corporation (UCC). MIC is used for producing carbamate pesticides, which are used in gardens and for agricultural purposes as well.

The Madhya Pradesh government's statistics show 3,787 died immediately. According to an affidavit filed in the Supreme Court by the Centre on October 26, 2006, more than 5.5 lakh people were injured. As per organisations, at least 20,000 have died over the years.

The medical management guidelines for methyl isocyanate published by the agency for toxic substances and disease registry says, "Methyl isocyanate is irritating and corrosive to the eyes, respiratory tract, and skin. Acute exposure to high vapor (vapour) concentrations may cause severe pulmonary edema and injury to the alveolar walls of the lung, severe corneal damage, and death. Survivors of acute exposures may exhibit long-term respiratory and ocular effects. Methyl isocyanate may be a dermal and respiratory sensitiser."

Even now, controversies over the reason for the disaster and compensation have not ended. Many are of the view that the Bhopal Gas Leak Disaster (Processing of Claims) Act, 1985, was not successful in meeting its objectives.

UCC paid $470 million in compensation in a settlement reached with the Union government, mediated by the Supreme Court of India.

"The unjust Settlement of 14/15.02.1989 was a complete sham with each gas victim being finally awarded less than one-fifth of the sum allotted even as per the terms of the settlement. As a result, the gas victims have had to wage concerted struggles in their quest for medical relief and rehabilitation, compensation, environmental remediation and justice," read a joint statement of Bhopal Gas Peedith Mahila Udyog Sangathan and Bhopal Gas Peedith Sangharsh Sahayog Samiti on Saturday.

Allegations of an improper judicial process have also been raised. The charges against Keshub Mahindra and six others (Union Carbide officials) were "diluted" from culpable homicide to rashness and negligence in 1996. They were convicted in 2010.

Allegations were also levelled against the Rajiv Gandhi government for "helping" Warren Anderson, CEO of UCC to leave India soon after the disaster. After he left the country, he was charged with culpable homicide. Requests for extradition was rejected by the US. Anderson died in 2014.